1. Field of the Invention
A valve assembly adapted for use with a refrigeration heat pump system wherein the reversal of refrigerant flow is accomplished upon operation of the valve assembly to provide either heating or cooling to a dwelling. The valve assembly has a movable valve member which moves in a cylindrical housing to change the straight through refrigerant flow in the valve. The valve member is operated by a pilot valve system operated by an external actuator.
2. Description of the Prior Art
Refrigeration changeover valve assemblies for providing the reversal of refrigerant flow in a refrigeration heat pump system, such as shown in the Frederick A. Greenwalt U.S. Pat. No. 2,976,701, issued Mar. 28, 1961, have been available for many years. In such changeover valve assemblies a continual desire is to have a minimum pressure drop through the valve, as small a size as possible, a minimum operating power requirement and most important, a low cost of manufacture. The prior art changeover valve assemblies generally have a piston valve member which is controlled by a pilot valve upon the operation of an external actuator so that when the piston valve member is moved, the flow is changed; however, refrigerant flow is greatly restricted in the valves.